branch: no detached HEAD check when editing another branch's description

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin/branch.c

@@ -822,11 +822,11 @@ int cmd_branch(int argc, const char **argv, const char *prefix)
 		const char *branch_name;
 		struct strbuf branch_ref = STRBUF_INIT;
 
-		if (detached)
-			die("Cannot give description to detached HEAD");
-		if (!argc)
+		if (!argc) {
+			if (detached)
+				die("Cannot give description to detached HEAD");
 			branch_name = head;
-		else if (argc == 1)
+		} else if (argc == 1)
 			branch_name = argv[0];
 		else
 			usage_with_options(builtin_branch_usage, options);